Sectional impervious hearth for fuel burners



May 11 1926. 1,584,331

J. SQUIRES SECTION AL IMPERVIOUS I-IEARTH FOR FUEL BURNERS Filed Dec. 1. 1924 g I Y Patented May 11, 1926.

UNITED STATES PATIENT) OFFICE.

JOHN SQUIRES, OF DETROIT, MICHIGAN, ASSIGNOR TO ECONOMIES RESEARCH COM- PANY, 0F HAVANA, ILLINOIS, A,CORPORATION OF ILLINOIS.

' S E CTIONAL IMPERVIOUS HEARTH FOR FUEL BURNERS.

Application filed December 1, 1924. Serial No. 753,056

My invention relates to fuel burning devices andmore particularly to a type of fuel burning devices adapted for domestic 1nstallation.

The object of my invention is in the provision of a hearth for use in connection with the so called rotary type of fuel burning devices, said hearth being impervious to unburned fuel, as well as substantially impervious to the intermittent intense temperature changes.

Another object of my invention is in the provision of a hearth for use in connect on with fuel burning devices said hearth being impervious to the unburned fuel and fashioned in a sectional manner for the purpose of ready installation and simplicity of structure.

A still further object of my invention is in the provison of a hearth member for fuel burning devices that is impervious to the unburned fuel and is fashioned in a manner to slightly retard the flow of unburned fuel therefrom.

A still further object of my invention is in the fashioning of a sectional hearth that has the advantagesxof simple installation and imp'erviousness to a liquid fuel.

Other objects of my invention will appear in the following specification, taken in connection with the annexed drawings in which, I

Fig. 1, is a perspective of a rotary fuel burner installation partially in, section for a more detailed view of the impervious hearth used in connection therewith.

Fig. 2, is a perspectve of one of the hearth sections and, Fig. 3', is adetail of one of the hearth sections showing the fuel retarding detent.

Referring to the drawings, I have shown in Fig. 1, a domestic rotary oil burner installation, without of course, all the formal fuel containing and supplying mechanism, or the control mechanismifor the burner, which forms no part of the present application. Although the present application is directed to the impervious hearth, nevertheless, this hearth is adapted mainly for use in connection with the so called type of fuel burners, namely rotary, the same being represented in the drawings generally as X.

The rotary burner dlsclosed in the present application has formed the basis for a co-pending application No. 719,0 t6, filed June 10th, 1924 by John Squires, the inventor of the present burner. Although a detailed description of said rotary burner was given in the above Inpntioned application, nevertheless, for the purpose of bringing out the advantages of the present sectional hearth, a general description of the burner will be made.

The burner as abbve stated, is of the rotary type and a cup member is adapted to re-- volve at a high rate of speed Within a combustion chamber and to project therefrom, a fuel mixture, the function of the peripheral speed of the fuel discor cup, being the atomization of the fuel.

In the present instance, the rotating cup is disclosed at 10, the same being revolved by means of an electric motor 11, transmit; ting power to the cup by means ofan'adjustable frictional connection 12, and a vertically dispose-d shaft 13. Fuel is fedrto the inner side of the atomizing cup 10, through a pipe 14:, there being a pump 15, operated by the electric motor for inducing the above mentioned flow. The fuel supplied through the tube 14, is discharged in a fan like spray from between the edges 16, of the rotating cup, by centrifugal action, and a supply of air to properly support ombus tion is induced by suction through the cup which is open at the lower end. A spark ignition of formal design is shown at 17,

said sparking mechanism being connected to any formal coil or spark inducing mechanlsm (not shown). Normally, rotation of the cup results in the fan like discharge of atomized fuel mixture which is immediately ignited by the sparking device. .1

The present application is directed mainl to the mannerof installation of the rotary burner with relation to the particular hearth used.

Rotary fuel burners of various types have been used for domestic installation for a considerable period of years and the manner of installation is substantially the same burned fuel and to protect the operating portions of the burner. Normally such installations include some sort 'of a cement ,atomizing cap. Applicant constructs hisimpervious hearth as follows:

An" abutment or protecting casing 18, of formal design, surrounds the burner in a manner to support a base 19, of brick. Radial supporting elements for the base 19, and support 18 are shown at 20. Upon the base 19, is rovided the fire clay non-combustible bac 'ng 21, of generally the same sweepas that of the retarding detents 23. The backing need not necessarily be fire clay and any non-combustible material might well be used. After the brick and cement base has been constructed, the hearth is then inserted thereover by merely placing the sections 22, side by side until they completely surround the burner or rather the rotary .cup. These sections are fash-' ioned in a manner to interlock at their edges and to abut closely the'supporting member 18, at their inner ends.

Each section is of metal and is impervious to the liquid fuel. The interlocking mechanism comprises the relative fashioning of the opposed edges of adjacent sections as shown in Figs. 2 and 3 of the drawings. The sections are installed in such manner that the open edge of the overlap, coincides with the direction of travel of the cup, and therefore prevents the passage of liquid fuel through the heartlr due to the centrifugal action of the atomizing cup. At a point adjacent the inner ends of each section are disposed detents 23. These detents are fashioned in such manner and in such location as to catch any fuel that is thrown into the hearth andthat naturally flows towards the lowermost point thereof, namely adjacent the burner. These detents merely retain a limited quantity of fuel and any considerable amount of fuel will result in overflowing the detents and passage thereof into a trough 24, adjacent the inner ends of the sections 22.

- The advantages of the above described sectional hearth are as follows:

Previously, hearths used in connection with the rotary ype of fuel burners have been constructed of brick and cement. Such hearths are not impervious to the intermittent and radical changes of temperatures, nor are they impervious to the liquid fuel used. Such hearths are dangerous in j that they absorb a certain quantityof comhustible fuel and are also impractical in that the intermittent temperature changes tend to crack them and provide other outlets for theoverflowing fuel in case of nonignition, than that necessarily provided.

The maintenance of-an integral and non-impervious hearth is essential to rotary burner construction in that this hearth is the means for controlling the burner under abnormal conditions, that is upon failure of ignition during operation ,of the burner and hence the dangerous accumulation of fuel. The

of argument.

the present device other than for the purpose Hearths not impervious to the unburned fuel, are naturally less impervious to the intermittent intense temperature changes that occur and for this reason disintegration will occur much sooner than where an impervious hearth, typified by the present application, is used.

Disintegration of the hearth destroys the quick operation of the overflow safety control mechanism above described.

The danger in the above situation, namely, disintegration of the' hearth, can not be minimized in that it comprises the most important element in the safety controls of fuel burning devices for domestic installation.

The above can be illustrated by the most frequent result due to this accumulation. We will say that the thermostat, (not shown) which controls the operation of the mrner, starts same with a simultaneous operation of the ignition mechanism, in the present instance, a spark. Now, for one of many reasons, ignition of the fuel mixture does not take place immediately, with the result that a' considerable amount of fuel is thrown upon the hearth and in case of a hearth that is not impervious, the fuel is retained in considerable quantities therein, either being absorbed by the non-impervious composition of the hearth or by crevices caused by disintegration. Now, when a late ignition takes place, there is on the hearth besides the normal fuel mixture discharge, this other accumulated fuel mix--- ture, which is readily ignitible and which -'n the small combustion chamber has been giving off gases that the normal draft of the furnace havevnot been able to take care of. This late ignition therefore results in an explosion, some times dangerous, the intensity of the -explosion being controlled directly by the amount of accumulated fuel. We can see readily that the normal small draft of the furnace will take off a certain amount of gas from this combustible fuel but in case of an amount considerably above normal, any late ignition of the discharging fuel mixture will result also in the ignition of this gas and hence a dangerous explosion.

With the present impervious hearth there can be no such danger in view of the fact that the un-ignited fuel mixture will flow under all conditions directl towards the inner ends of each section amf into the over,- flow. As a matter of fact, to prevent the almost instant passage of the fuel into the overflow pipe, a series of small detents' 23,

These defuel into the overflow and hence to the safety control mechanism. Normally, of course, ignition will talre place almost instantly and even in case it is late there will not be a dangerous accumulation of fuel in the hearth. As a matter of fact, in' case there is a failure of ignition the resultant flow of unburned fuel will soon overflow the detents, pass into the overflow pipe and cut out the burner. However, if ignition takes place very shortly but not instantly, any accumulation .of fuel in the detents will soon be burned up.

Although I have illustrated a hearth made up of a plurality of metal sections, imperv 1ous to the unburned fuel, nevertheless, my invention includes any hearth not impervioust'o the unburned fuel, for instance of the glazed ceramic type. Glazed ceramic hearths as well as metal hearths, besides being' impervious to the unburned fuel, are likewise true refractories, and consequently assist in the promotion ofgood combustion. In the case of the metal hearth and the fact that it can consequently be made much thinner its rise to high temperature is very rapid and therefore, proper combustion can be developed more quickly than any other type.

Another advantage in the .metal hearth,

would be the fact. that it is not perishable when -non-oxidizing material is used.

WhatI claim is: i 1. In a fuel burning device, comprising a rotary atomizer adapted to project an atomizedfuel mixture into a zone of ignition, a combustlon hearth composed of non-combustiblemateria1 surrounding said atomizer, I

and a plurality of overlapping metal sections I conforming to the hearth, said sections being fashioned to provide admin for the condensed fuel mixture upon'failure ofcombustion conditions during burner activity.

2. In a fuel burning device, comprising an atomizer adapted to project an atomized fuel mixture" into a zone of ignition. a combustion hearth composed of non-combustible material and a lurality of overlapping metal sections con orming to the hearth, said sections being fashioned to provide a drain for any unignited condensed fuel occasioned by a failure of combustion conditions during burner activity.

3. In a fuel burning device, comprising a rotary atomizer adapted to project an atomizedifuel mixture into a zone of ignition, a combustion hearth composed of non-combustible material surrounding said atomizer, and a plurality of metal sections conforming to the hearth, said sections having their opposed edges fashioned for'relative interlock in the direction of the fuel discharge and providing a drain for the condensed fuel mixture upon a failure of combustion conditions during burner activity.

4. In afuel burning device, comprising a rotary atomizer adapted to project an atomized fuel mixture into a zone of ignition, a combustion hearth composed of non-combustible material surrounding said atomizer, and a plurality of overlapping metal sections conforming to the hearth and providing a drain for the said condensed fuel mixture upon a failure of combustion conditions during burner activity, said metal sections being fashioned in a manner to retard slightl the draining action of the condensed fuel t erefrom.

In testimony whereof I aflix m signature.

- JOHN S UIRES. 

